1. Field of the Invention
The invention relates to an apparatus for shortening and/or fastening a flat belt or strap for wrapping and hoisting a load.
2. Background of the Prior Art
In the prior art, high-strength flat belts or straps have frequently been used to hoist loads. Belts or straps have advantages over ropes or chains in a number of practical applications, in particular for hoisting fragile merchandise, machine parts, motor vehicles, etc. In addition, the handling of such straps or belts requires less physical exertion on the part of the operators and handling personnel. Thus, there is the advantage of allowing more rapid and efficient loading and unloading. There are similar advantages to the use of high-strength woven synthetic straps or belts in lashing loads for shipment.
Belts or straps are also suitable for hoisting heavy loads because, in contrast to cables or chains, significantly less labor is required to fasten them. Also, damage to the merchandise caused by metal lashing elements of cables or chains can be prevented if straps or belts are used. However, in contrast to chains, for example, a belt or strap is not as easy to shorten to the optimal or required length. For attachment to crane hooks, therefore, such belts in conventional applications are reinforced, at least on the ends, and are fitted with sewn loops.
Moreover, for merchandise or loads which must be slung in a particular manner, it is necessary to maintain a rather large inventory of belts or straps of different lengths or with different fittings. This makes the loading and unloading more expensive and more complicated. Since it requires additional material and labor, it contributes to an undesirable increase in loading and unloading costs.
DE-OS 30 42 364 describes an apparatus for lashing and fastening a strap, in which the strap has a ready-made loop on one end, and the other end is inserted or threaded into the apparatus. To shorten the strap, it is first pulled through the apparatus. Then, to lash or hoist a load or merchandise, it is fastened tight. The prior art includes a number of equivalent and similar devices, including so-called turnbuckles, e.g. as described in DE-PS 32 03 750. However, on the one hand, such devices are relatively expensive and complicated, while, on the other hand, they are not suitable for large loads.
Apparently, therefore, the prior art lacks an absolutely uncomplicated, heavy-duty, low-maintenance, easy-to-operate apparatus suitable for hoisting or lashing heavy loads by means of belts or straps of the type described above on a crane hook. Additionally, the prior art fails to provide an apparatus which eliminates the need for ready-made loops on the ends of the straps or an assortment of different lengths of straps or belts, and at the same time makes it possible to easily shorten the belt or strap as necessary.